Lock assembly

ABSTRACT

A lock assembly is provided which has particular utility in hotels and motels, or other places where a change of occupancy frequently occurs. The lock to be described has approximately the same shape and size as the usual prior art door locks, so that it may readily be mounted in existing doors to replace existing locks. The lock includes a removable logic element which serves to change the lock for each change of occupancy. In addition, logic elements are provided, which are independent from the first-mentioned logic element, and which permit the lock to be operated by other keys, such as a maid&#39;&#39;s key or a master key, each of which is independent from the others, and each of which operates independently of the others. A latching mechanism is provided, which may be manually operated from inside the door by the occupant of the room, to restrict operation of the lock to one key only, for example, the master key, when privacy is desired. In the embodiment to be described, the lock includes a plurality of tumblers which are mounted on separate coaxial carriers which are turned relative to one another as the keys operate the lock.

United States Patent Raymond et al.

[ June 24, 1975 LOCK ASSEMBLY [76] Inventors: James W. Raymond, 300 Avenida Cumbre, Newport Beach, Calif. 92660; James A. Millett, 18143 Firestone Ct., Fountain Valley, Calif. 92708 22 Filed: Feb. 19, 1974 [21] App]. No.: 443,310

[52] US. Cl. 70/363; 70/385; 70/DlG. 6O

[51] Int. Cl. E05b 27/08 [58] Field of Search 70/363, 404, 384, 383,

70/385, 276, 382, DIG. 60, 339

[56] References Cited UNITED STATES PATENTS 1,610,224 12/1926 Dalboni 70/385 X 3,817,066 6/1974 Pearson 70/363 Primary ExaminerRobert L. Wolfe Attorney, Agent, or Firm-Jessup & Beecher [5 7 ABSTRACT A lock assembly is provided which has particular utility in hotels and motels, or other places where a change of occupancy frequently occurs. The lock to be described has approximately the same shape and size as the usual prior art door locks, so that it may readily be mounted in existing doors to replace existing locks. The lock includes a removable logic element which serves to change the lock for each change of occupancy. In addition, logic elements are provided, which are independent from the first-mentioned logic element, and which permit the lock to be operated by other keys, such as a maids key or a master key, each of which is independent from the others, and each of which operates independently of the others. A latching mechanism is provided, which may be manually operated from inside the door by the occupant of the room, to restrict operation of the lock to one key only, for example, the master key, when privacy is desired. In the embodiment to be described, the lock includes a plurality of tumblers which are mounted on separate coaxial carriers which are turned relative to one another as the keys operate the lock.

7 Claims, 14 Drawing Figures aura/0e M205 ../0/

PATENTEIJJUN 24 I915 SHEET PATENTEDJUN 24 I975 SHEET Fla 111 12 LOCK ASSEMBLY RELATED COPENDING APPLICATION Ser. No. 438,867 filed Feb. 1, I974.

BACKGROUND OF THE INVENTION Although the specification herein will be directed to hotels and motels, for convenience of description, it will become evident as the description proceeds that the improved lock of the present invention is not limited to such uses, but is useful in many other areas such as in business offices, industrial plants, government facilities, and in other locations where changes in occupancy frequently occur, and where master keying is used.

As described in the aforesaid Copending Application, problems have arisen in recent years in the prevention of theft of hotels and motels due to the unauthorized use of the room keys issued to the guests and maids. Such keys are often lost, stolen, or otherwise find their way into the hands of unauthorized persons. However, in accordance with the present invention, the lock is changed for each change of occupancy, so that the previous key has no further utility in opening the lock. In fact, the key itself may be disposable, and there is no need for the guest to return it upon checking out of the hotel.

The basic purpose of the invention described in the Copending Application, therefore, is to provide a lock assembly which may be set to match a particular key for each new occupancy of the room, this being achieved by inserting a guest logic member into the lock from the inside of the door. The guest logic member establishes a certain pattern in a first group of tumblers within the lock, to permit the door to be unlocked only when a mating key is inserted into the lock. With such an assembly, no particular lock permanently matches any particular key, and each lock in the hotel is temporarily set for the duration of each occupancy to be operated by a particular key by the insertion of a complementing logic member.

The embodiment of the present invention to be described has approximately the same shape and size as existing locks, so that such existing locks may be easily replaced by locks constructed in accordance with the invention. When a hotel is equipped with the locks of the invention, complete flexibility is achieved since no door lock permanently requires any particular key, and each lock responds to any complementing logic and key combination.

Since the tumbler combination of the lock of the invention is changed for each new occupancy, the problem of lost or stolen keys is solved, and each new guest has the security of knowing that there are no previous keys available which are capable of operating his lock. Another advantage of the lock of the invention is that it is capable of operation by means of relatively inexpensive and disposable logic members and keys.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side sectional view showing a lock assembly constructed to incorporate the concepts of one embodiment of the invention;

FIG. 2 is a left end view of the assembly of FIG. 1, with the outer knob removed to reveal certain operating components of the invention;

FIG. 3 is a perspective representation of a subassembly of the lock of FIG. 1 incorporating a primary tumbler carrier and primary tumblers for the lock;

FIG. 4 is a further sub-assembly perspective view, showing secondary tumblers of the lock of FIG. 1, and a secondary carrier;

FIG. 5 is a further sub-assembly perspective view of the lock of FIG. 1, showing the secondary tumbler carrier, also showing an additional carrier for a plurality of different logic members, as will be described;

FIG. 6 is a further sub-assembly perspective showing of the secondary tumbler carrier assembled on the primary tumbler carrier;

FIG. 7 is a side section of a guest logic member which may be removably inserted into the lock;

FIG. 8 is a top plan view of the guest logic member of FIG. 7;

FIG. 9 is an end view ofa maids logic member which also is supported within the lock, and the embodiment to be described;

FIG. 10 is a section of the maids logic member of FIG. 9, taken essentially along the line 1010 of FIG.

FIG. 11 is an end view of a master logic member which also is mounted in the lock in the embodiment to be described;

FIG. 12 is a section of the master logic member of FIG. 11, taken along the line 1212 of FIG. 11;

FIG. 13 is a side section of a key which may be used in conjunction with the lock of FIG. 1; and

FIG. 14 is a side elevation of the key of FIG. 13.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT The lock assembly, in the embodiment of the invention to be described, and as shown in FIG. 1, includes an outside door knob 10 and an inside door knob 12 separated by a door, a fragmentary portion of which is designated 11. The outside knob 10 includes a central annular keyhole which receives a cylindrical key 102 (FIGS. 13 and 14). The key 102 engages four primary tumbler drive pins 104. The end of key 102 is formed into four quadrants of different lengths, in accordance with a particular code, and these quadrants move the pins 104 to the left in FIG. 1 to corresponding set linear positions. A pair of primary tumblers 106 is formed on the inner end of each pin 104, as best shown in FIG. 3. The pins 104 and tumblers 106 are supported in an inner tubular primary carrier 110, which is keyed to a coaxial central shaft 112.

The drive pin 104 which is displaced the greatest distance to the left in FIG. 1 by the insertion of the key 102 in the annular keyhole 100 engages the right-hand end of an outer secondary tubular tumbler carrier 114, and it moves the carrier 1 14 to the left in FIG. 1 against the bias of a spring 116, as the key is pushed into the keyhole. A plurality of secondary tumbler drive pins 118, for example four, are carried by the carrier 114, and each pin 118 has a secondary tumbler 120 formed at its inner end.

As the carrier 114 is moved to the left in FIG. 1 by the insertion of the key 102, the pins 118 move with it until they engage corresponding ones of four idler pins 122. The four idler pins 122 are carried in a tubular carrier 124 which is fitted into the inside door knob 12, to the left in FIG. 1, and each idler pin 122 is freely slidable axially in the carrier. The axial position of each idler pin 122 is set by a cylindrical guest logic member 126 which is fitted cylindrically into the tubular carrier 124. The guest logic member 126, as shown in FIGS. 7 and 8, includes an outer tubular member which has four axially extending quadrants of different axial lengths to complement the four quadrants formed in the key 102 of FIGS. 13 and 14, described above. The four quadrants of the guest logic member 126 are positioned in a circular path at equi-angular positions, and each has a predetermined arcuate width.

The idler pins 122 are included in the assembly to prevent access to the inside of the lock when the guest logic member 126 is removed, and they serve to couple the four quadrants of the guest logic member to the secondary tumbler pins 118, so that the axial position of each pin 118 and each secondary tumbler 120 is determined by the axial length of the guest logic quadrants. When the guest logic complements the quadrants on the key 102, the relative positions of the primary tumblers 106 and of the secondary tumblers 120 is such that the key may be turned to unlock the door.

When there is no key in the lock, the primary tumblers 106 and the secondary tumblers 120 are normally in relative positions such that the door could be opened. To prevent this, a longitudinally projecting integral tongue 114a of the secondary carrier is received in an angular groove 110a (FIG. 6) in the forward end of the primary carrier 110 to prevent rotation of the carrier 110 within the secondary carrier 114. Therefore, when there is no key in the lock, the door cannot be opened from the outside. The carrier 114 is biased into the position of FIG. 6 by the spring 116 of FIG. 1.

The inner tubular primary carrier 110 is coupled to a latch pull cam 163 (FIG. 2) by a longitudinal projection 165; so that when the primary tumblers 106 are in alignment with the secondary tumblers 120, the primary carrier 110 is able to rotate within the outer secondary tumbler carrier 114, thereby retracting the latch 162.

When the key 102 is inserted into the annular keyhole 100 the secondary carrier 114 is shifted to the left in FIG. 6, to free the tongue 114a from the groove 110a in the primary carrier 110. Then, if the primary and secondary tumblers are set to matching positions, the carrier 110 can be turned in the carrier 114 by the key 102. The angular distance through which the carrier 110 may then be turned in the carrier 114 is determined by the angular groove 110b of FIG. 3. This angular distance is sufficient to permit the primary carrier 110 to be turned sufficiently to retract the latch 162 of FIG. 2.

The outer secondary carrier 114 is able to turn a limited amount in the frame of the assembly, but rotation is limited by a fixed pin (not shown) which engages a selected one of the grooves 114b, 1140, 114d, (FIG. in the secondary carrier 114. When a guest key 102 is inserted into the keyhole 100, the secondary carrier is moved to the left in FIG. 5 without turning, and this movement of the secondary carrier causes the pin to enter the groove 1l4b. The secondary carrier 114 is then held in a fixed angular position such that the pins 118 are lined up with the idler pins 122. Then, if the axial lengths of the qudrants of the guest key 102 complement the axial lengths of the quadrants of the guest logic member 126, the tumblers will match; and the door may be unlocked by turning the key, which turns the primary carrier 110 in the secondry carrier 114.

The primary tumblers 106 have serrations at predetermined distances along their entire leading edges. The secondary tumblers 120 are round and have serrations at predetermined distances around their circumferences as best shown in FIG. 4. When the primary tumblers 106 are not in alignment with the secondary tumblers 120, the serrations of the primary tumblers 106 will interlock with serrations of the secondary tumblers 120, thereby preventing relative axial movement between the primary tumblers 106 and the secondary tumblers 120. It is therefore impossible to detect the relative alignment positions of primary tumblers 106 with secondary tumblers 120 externally, so that the lock is virtually pick-proof.

However, in the case of the maids key, the rib 102b is displaced angularly from the rib 102e, as shown in FIG. 14, so that as the maids key is inserted into the keyhole a predetermined distance, it must then be turned, for example, through I5", before it can be completely inserted into the lock. this turning of the maids key causes the primary carrier 110 and the secondary carrier 114 to turn 15 so that the ends of the pins 118 are turned away from the idler pins 122. The pins 118 now become aligned with rod-like prongs 204 of a maids logic member 206 (FIGS. 9 and 10), which is carried on the inner end of the logic carrier 124 of FIG. 1. The maids logic member 206 is not shown in place in FIG. 1, for purposes of clarity. It is to be understood, however, that the maids logic member 206 is carried on the reduced diameter inner end of the carrier 124 adjacent the illustrated annular shoulder of the carrier with the prongs 204 of the maids logic member 206 extending longitudinally towards the right in FIG. 1 adjacent the pins 122, but displaced angularly 15 from the pins. Then, as the key is further inserted into the lock to move the secondary carrier 114 to the left in FIG. 1, the aforesaid fixed pin of the secondary carrier 114 enters groove 1140 of FIG. 5, and the secondary tumblers 120 turn with the turning of carrier 114 to be aligned with the prongs 204 of the maids logic member 206 and they are set by the prongs 204 of the maids logic member 206 to axial positions determined by the length of the prongs 204 of the maids logic member 206. In this way a different logic condition is established for the secondary tumblers 120, which must be complemented by the axial lengths of the quadrants of the maids key, before the maids key will unlock the door.

Likewise, for the master key, the rib 102b of the key 102 of FIGS. 13 and 14 is displaced, for example, 30 from the rib 1026. Therefore, when the master key is inserted into the keyhole 100, it must be turned when it reaches an intermediate position, and this turning of the key turns the primary carrier assembly 110 and the secondary carrier 114 through 30 to align the pins 118 with the rod-like axial prongs 200 of the master logic member 202 of FIGS. 11 and 12. The master key may then be fully inserted to the end of its travel within the lock to set the secondary tumblers 120, and when the setting is complemented by the quadrant lengths of the master key, the primary tumblers 106 are set in the proper positions to permit the master key to unlock the door. The master logic member 202 is received coaxially with the maids logic member 206 on the inner end of the carrier 124. The master logic member 202 is, therefore, positioned on the inner end of the carrier 124 against the maids logic member 206, but with its prongs 200 turned from the prongs 204 of the maids logic member. Therefore, when the master key is inserted in the lock, it turns the secondary carrier 114 through as mentioned above, so as to align the pins 118 with the prongs 200 of the master logic member 202.

It will be appreciated that as the secondary carrier 114 is turned. and then moved to the left to engage the maids logic member 206 by the insertion of the maids key into the lock, the aforesaid pin of the secondary carrier 114 is received in the slot 114: of FIG. 5, as mentioned above. Likewise, when the carrier 114 is turned, and then moved to the left to mate with the master logic member 202 by the insertion of the master key in the lock, the aforesaid pin is received in the slot 114d of FIG. 5. The slots 114b, 1140 and 11411 assure, therefore, that when the secondary carrier 114 has been turned to any one of its three angular operating positions, it will be held against any angular rotation when in that operating position, until the particular operation has been completed.

As shown in FIG. 2, the inner knob 12 is coupled to the latch pull 160 through the cam 163, so that whenever the inside door knob 12 is turned, the latch pull member 160 pulls the latch 162 to open the door. A longitudinal projection 165, which is integral with the cam 163, couples the cam to the locking assembly described above, so that when the carrier 110 is free to turn, it moves the projection 165 along an arcuate path to operate the latch pull 160.

The logic carrier 124 is fixed to the outer sleeve of the lock by a pin 150 (FIG. 1), so that the carrier 124 remains angularly stationary at all times. The carrier 124 can be removed to replace the maid logic member 206 and the master logic member 202, both of which are supported on its inner end, only when a master key has been inserted into the lock to turn the entire carrier assembly to the master logic position, and only when the shafts 112 and 132 are turned to the door-opened position. Under such conditions, appropriate index slots line up to permit a pin (not shown) on the logic carrier 124 to pass through the index slots so as to permit the logic carrier 124 to be removed. This feature assures that although the guest logic member may be readily removed to accommodate each new occupant of the room, the maid's logic member and the master logic member are hidden from view, and may only be removed when the lock is operated by the master key, so as to prevent tampering with the lock by the guest or maid.

The guest logic member 126 of FIGS. 7 and 8 has four radial projections 126a, 126b, 126d positioned around its periphery. These projections are received in corresponding axial slots in the logic carrier 124. .The projection 126b is larger than the other projections, and it is received in a larger slot in the logic carrier, to assure a particular angular orientation of the guest logic member 126 with the logic carrier 124.

The guest logic member 126 has a handle 126e, as shown in FIG. 8, by which the guest logic member may be turned in the carrier 124 to a lock position in which the entire carrier assembly within the lock is turned to align the pins 118 with the master logic member, so that the assembly is in the master key position. It is held in that position by a projection not shown) on the latch pull 160 of FIG. 2 so long as the guest logic member has turned the carrier assembly to the Lock position. When the carrier assembly is in the Lock position, only the master key can open the lock, and the maids key and guest key are both ineffective. This assures privacy to the occupant of the room, but it still permits the master key to unlock the door in the case of emergencies. When the tumbler carrier assembly is turned to the Lock position by the guest logic member 126, and after the inside door know has been turned to open the door, or the latch bolt is pushed in by closing the door, the tumbler carrier assembly is automatically turned back to its normal position by a spring 108 (FIG. 1).

The guest logic member 126 of FIG. 7 has an inner split tubular portion 126f which is received on the end of the shaft 130, and which has a projection 126g that is received in an axial groove on the shaft 130. The guest logic member 126 is inserted into the opening in the carrier 124, and is moved along the shaft 130 until the projection 126g engages the groove in the shaft 130, and the logic member 126 is then turned on the shaft 130 to hold the guest logic member firmly on the shaft in a bayonet-type coupling arrangement. The guest logic member 126 can be removed only when the shaft 130 is turned to its door-open position in which the latch pull of FIG. 2 pulls the latch 162 to its right-hand position.

The outer tubular portion 12611 of the guest logic member 126, as shown in FIG. 7, has axial slots formed in it to provide the four axial quadrants, and the inner ends of the quadrants are formed to different lengths to complement the quadrants of the corresponding guest key 102 of FIGS. 13 and 14. The prongs 204 of the maid logic member 206 of FIG. 10 are formed to different axial lengths to complement the quadrants of the maids key. The maids logic member is provided with an extra prong 205. The master logic member 202 of FIG. 11 has its prongs 200 formed to different axial lengths to complement the quadrants on the master key. The master logic member 202, also, is provided with an extra prong 201. The extra prongs 205 and 201 of the maid and master logic members are received in appropriate slots in the carrier 124 to assure that the maids logic member 206 and the master logic member 204 will each have the correct angular positions on the logic carrier 124.

It will be appreciated that if the guest logic member 126 is removed, a blank key could be inserted in the keyhole 100 in the outside knob to unlock the door. Therefore, an additional logic member, which may be termed a bellmans logic member is provided, and the bellmans logic member is inserted into the carrier 124, for example, by the maid, whenever a guest has chcked out and the room is ready for the next occupant. The bellmans logic member is structurally similar to the guest logic member 126. The bellmans key is constructed to complement the bellma ns logic member. Therefore, when the bellman escorts a new guest to the room, he unlocks the door with his key, and he then removes the bellmans logic member, and inserts the new guests logic member, so that the door may be conditioned to be unlocked by the guest key which was issued to the new guest.

As described above, the guest logic member 126 can be removed from the logic carrier 124 whenever the door is unlocked by a complementing key, and after the complementing key has been turned to a door unlocked position. However, as also described, the

maids logic member and the master logic member are hidden in the assembly, and cannot be removed unless the logic carrier 124, itself, is removed. As also described, the logic carrier 124 can be removed only when a master key is used to open the door, and after the master key has subsequently been turned to the door unlocked" position.

The invention provides, therefore, an improved lock assembly which is constructed to have approximately the same size and shape as existing locks, so that it can readily replace existing locks in the doors of hotel rooms, or the like, and which may be set for each new occupant of the room.

The lock assembly of the invention has a feature that a maid may obtain access to the room through the use of her key, which is independent from the guests key, and which operates on a logic member within the lock which is independent of the logic member operated by the guest key. The maids key may be such to permit access by the maid to a number of rooms, each of which has different guest logic members inserted in the locks, and each of which requires a different guest key to unlock the door. In addition, the management may obtain access to the room, or lock out the guest and maid, by the use of the master key which operates yet another logic member independently of the other two logic members.

Also, as described above, provisions are made to permit the occupant to lock out the maid when he is in the room, if he so desires. However, although the maid can be locked out of the room by the occupant, the master key can still be used to gain access to the room, which may often be desirable in the case of an emergency.

A further feature in the embodiment described above is the fact that the master logic member and the maid logic member are hidden within the lock assembly it self, and they can only be removed by use of the master key, as previously described. This permits the locks to be virtually tamper-proof.

It will be appreciated that although a particular embodiment of the invention has been shown and described, modifications may be made. It is intended in the following claims to cover all the modifications which come within the spirit and scope of the invention.

What is claimed is:

1. A lock assembly including: a casing; a first tubular carrier mounted in said casing; a second tubular carrier mounted in said casing coaxially with said first carrier; a tubular logic carrier mounted in said casing at a first end thereof coaxially with said first and second tubular carriers; a first tubular logic member mounted coaxially in said tubular logic carrier and having axially extending quadrants of different lengths; a first plurality of pins mounted on said first carrier at angularly spaced positions around the axis thereof and individually axially movable in said first carrier; a first plurality of tumblers respectively mounted on the ends of said pins remote from said first tubular logic member and individually settable to different axial positions established by the lengths of the quadrants of said first logic member; a second plurality of pins mounted on said second tubular carrier at angularly spaced positions about the axis thereof displaced axially towards the other end of the casing and individually axially movable with respect to said second carrier; a second plurality of tumblers respectively mounted on the pins of the second plurality at the ends thereof adjacent the tumblers of the first plurality; and means for receiving a key in said other end of said casing to engage the pins of the second plurality and to set the tumblers of the second plurality at different axial positions to a predetermined relationship with respect to the positions of the tumblers of the first plurality to permit the second carrier to be turned relative to the first carrier.

2. The lock assembly defined in claim 1, in which the tumblers of the first plurality and the tumblers of the second plurality have serrations thereon to prevent picking the lock.

3. The lock assembly defined in claim 1, and which includes a second tubular logic member mounted coaxially on said tubular logic carrier adjacent said first logic member and having axially extending rod-like prongs angularly displaced from the quadrants of the first logic member, said first and second carriers being turnable by a first key to turn the ends of the pins of the first member and to align the ends of the pins of the first plurality with the prongs of said second logic member.

4. The lock assembly defined in claim 3, and which includes a third tubular logic member mounted coaxially on said logic carrier adjacent said second logic member and having axially extending rod-like prongs angularly spaced from the prongs of said second logic member, said first and second carriers being turnable by a second key to align the ends of the pins of the first plurality with the prongs of said third logic member.

5. The lock assembly defined in claim 4, in which said first logic member is turnable in said casing to turn said logic carrier to an angular position in which the prongs of the third logic member are aligned with the ends of the pins of the first plurality.

6. The lock assembly defined in claim 3, in which the first key has a longitudinal rib which is received in a slot in the lock assembly to turn said first and second carriers, so as to move the pins of the first plurality angularly from the quadrants of the first logic member to an axially aligned position with respect to the prongs of the second logic member.

7. The lock assembly defined in claim 1, in which said first logic member is mounted in said tubular logic carrier to be exposed through the first end of the casing, and in which the second and third logic members are carried on the inner end of the tubular logic carrier to be hidden thereby from said first end of the casing. 

1. A lock assembly including: a casing; a first tubular carrier mounted in said casing; a second tubular carrier mounted in said casing coaxially with said first carrier; a tubular logic carrier mounted in said casing at a first end thereof coaxially with said first and second tubular carriers; a first tubular logic member mounted coaxially in said tubular logic carrier and having axially extending quadrants of different lengths; a first plurality of pins mounted on said first carrier at angularly spaced positions around the axis thereof and individually axially movable in said first carrier; a first plurality of tumblers respectively mounted on the ends of said pins remote from said first tubular logic member and individually settable to different axial positions established by the lengths of the quadrants of said first logic member; a second plurality of pins mounted on said second tubular carrier at angularly spaced positions about the axis thereof displaced axially towards the other end of the casing and individually axially movable with respect to said second carrier; a second plurality of tumblers respectively mounted on the pins of the second plurality at the ends thereof adjacent the tumblers of the first plurality; and means for receiving a key in said other end of said casing to engage the pins of the second plurality and to set the tumblers of the second plurality at different axial positions to a predetermined relationship with respect to the positions of the tumblers of the first plurality to permit the second carrier to be turned relative to the first carrier.
 2. The lock assembly defined in claim 1, in which the tumblers of the first plurality and the tumblers of the second plurality have serrations thereon to prevent picking the lock.
 3. The lock assembly defined in claim 1, and which includes a second tubular logic member mounted coaxially on said tubular logic carrier adjacent said first logic member and having axially extending rod-like prongs angularly displaced from the quadrants of the first logic member, said first and second carriers being turnable by a first key to turn the ends of the pins of the first member and to align the ends of the pins of the first plurality with the prongs of said second logic member.
 4. The lock assembly defined in claim 3, and which includes a third tubular logic member mounted coaxially on said logic carrier adjacent said second logic member and having axially extending rod-like prongs angularly spaced from the prongs of said second logic member, said first and second carriers being turnable by a second key to align the ends of the pins of the first plurality with the prongs of said third logic member.
 5. The lock assembly defined in claim 4, in which said first logic member is turnable in said casing to turn said logic carrier to an angular position in which the prongs of the third logic member are aligned with the ends of the pins of the first plurality.
 6. The lock assembly defined in claim 3, in which the first key has a longitudinal rib which is received in a slot in the lock assembly to turn said first and second carriers, so as to move the pins of the first plurality angularly from the quadrants of the first logic member to an axially aligned position with respeCt to the prongs of the second logic member.
 7. The lock assembly defined in claim 1, in which said first logic member is mounted in said tubular logic carrier to be exposed through the first end of the casing, and in which the second and third logic members are carried on the inner end of the tubular logic carrier to be hidden thereby from said first end of the casing. 